The present invention relates to a flip cover assembly for a cellular phone or the like and, in particular, to a flip cover assembly utilizing a cam member to provide a positive open and closed position with a unique feel and lasting mechanical life.
In the design of cellular telephones and similar communications technology, it is desirable to have a mechanical flip cover that can be used to answer and terminate a call, protect the keypad and contain a microphone. When using a flip cover, it is desirable to have positive open and closed positions without significant play in the range of motion of the flip cover.
Many solutions have been provided for this problem in the past. One elaborate design includes a viscously-damped torsional spring with a latch that will keep the flip cover closed until it is released via a button. Still other designs rely on a simple mechanical interference like a small dimple in one of the mating halves, which has a mating bump specifically located for the open and closed positions. In the dimple design, the flip cover naturally wants to be in the mated position due to the deflection of the plastic when in the unmated position. A still simpler design includes a simple hinge (shaft in hole) that has a certain amount of interference between the shaft and the hole to prevent the assembly from moving too freely.
These conventional designs, however, suffer from various drawbacks. In particular, the torsional spring arrangement adds significant cost to the device. Although it provides the nicest feel and action, the added cost greatly hinders its success. The dimple design provides a desirable tactile feel and positive open and closed positions; however, due to the friction and force between the dimple and the bump, the material often deforms over time, and the assembly becomes less desirable. Finally, the simple hinge provides no positive open and closed positions and also becomes loose over time.